• Korean Journal of Microbiology
• /
• v.48 no.3
• /
• pp.180-186
• /
• 2012

Pseudomonas aeruginosa, a Gram-negative bacterium, is an ubiquitous and opportunistic human pathogen, which expresses many virulence factors through quorum sensing (QS) regulation. QscR, one of the QS signal receptors of P. aeruginosa, has unique features that make it possible to distinguish QscR from other QS receptors. In the present study, we focused on amino acid residues responsible for such a broad signal specificity of QscR. Thus we constructed mutant QscRs: $QscR_{T72I}$, $QscR_{R132M}$, and $QscR_{T140I}$ by substituting $72^{nd}$ threonine, $132^{nd}$ arginine, and $140^{th}$ threonine residues with isoleucine, methionine, and isoleucine, respectively by site-directed mutagenesis. When we examined the activity of these mutant QscRs, $QscR_{R132M}$ failed to respond to N-3-oxododecanoyl homoserine lactone (3OC12-HSL), but $QscR_{T72I}$ and $QscR_{T140I}$ remained the ability to respond to 3OC12-HSL despite much reduction of the sensitivity. When we treated a variety of acyl-HSLs with different structure, $QscR_{T72I}$ and $QscR_{T140I}$ showed better responsiveness to N-decanoyl HSL (C10-HSL) or N-dodecanoyl HSL (C12-HSL) that has no oxo-moiety at $3^{rd}$ carbon of acyl group than to 3OC12-HSL, and $QscR_{R132M}$ showed no responsiveness to any acyl-HSLs tested here. In addition, $QscR_{T72I}$ and $QscR_{T140I}$ were inhibited by 5f, a QscR inhibitor as similarly as wild type QscR was. These results suggest that while the $130^{th}$ arginine is crucial in both activity and acyl-HSL binding of QscR, the $72^{nd}$ and $140^{th}$ threonines are important in the activity, but they are little responsible for the discrimination of acyl-HSLs or competitive inhibitor.

• Journal of Korean Society for Quality Management
• /
• v.49 no.1
• /
• pp.61-79
• /
• 2021

Purpose: The purpose of this study is to study the relative weights of Quality Scorecard (QSC) which was developed for a new quality concept, called Open Quality, in the era of Industry 4.0. Open Quality aims to ensure quality responsibility by accurately measuring the quality level and sharing the quality data with stakeholders. Methods: To analyze the importance of QSC, a survey study was conducted based on 10 types of industry. The relative weights of QSC measures are investigated by both the industry types and the organizational life cycle. Further, the relative importance of QSC was analyzed according to the organization's lifecycle. By dividing the aspects with respect to the result data, application method for QSC is further provided. Results: The result indicates that there are significant differences among Korean companies in terms of the level of Industry revolution stages. Among ten industry types, manufacturing and finance sectors show the highest importance of QSC. QSC measures are also considered more importance in growth stage of the maturity cycle than generator and decline stages. Conclusion: When QSC is adopted for Open Quality, its relative weights must be considered to cope with the unique characteristics of industrial types. Besides, QSC's contribution may vary according to the level of maturity of the target company.

• Proceedings of the Korean Fiber Society Conference
• /
• 2003.04a
• /
• pp.400-401
• /
• 2003

섬유제품의 생산방식이 다품종 소량생산체제로 전환함에 따라 빈번한 직물교체에 따르는 작업시간을 줄이기 위한 방법으로 위한 소위 QSC(Quick Style Change)의 개념이 도입되고 있다. QSC에서는 특히 백레스트 시스템을 위시한 직기의 각종 경사장력 조절시스템을 신속히 설정하는 것이 핵심적인 사항이다. 특히, QSC를 위하여 실제 제직을 하지 않고서도 경사장력조절시스템의 설정 상태에 따라 경사의 장력 거동을 예측할수 있는 경사장력 컴퓨터모사기술이 유럽의 여러나라들에서 최근까지 개발되고 있다[1-3]. (중략)

• Journal of the Korean Society of Food Culture
• /
• v.5 no.4
• /
• pp.455-462
• /
• 1990

The purpose of this study were to investigate relationships between the franchisors and franchisees in terms of management, satisfaction and cooperation, and to establish a model for improvement of the foodservice management structure of fast food franchise system. Data were collected from 4 hamburger and 7 noodle franchisors, and from 21 hamburger and 38 noodle franchisees. Surveyed chains were composed of 10 franchisor-owned units and 49 franchised units. The instrument used in this study was Liker type 5-scale guestionnarie. Hypotheses concerning relations between management practices by franchisor and satisfaction of franchisee, cooperation of franchisee were tested using path analysis. Unit management practices by franchisors were significantly different according to the operation style. Franchisor-owned hamburger chains rather than franchised noodle chains were better managed by franchisors in terms of QSC and management support. Management practices by franchisors in the whole showed a significant relationship with the satisfaction, cooperation, and the implementation of standardized recipes by franchisees. Franchisees' satisfaction had a significant positive relation with the cooperation and the implementation of standardized recipes. QSC management practices and management support by franchisors, had no direct relevance to the general cooperation of franchisees, and management practices in the whole had a little relevance to it, but franchisees' satisfaction in terms of QSC and the whole had a strong effect to their QSC Cooperation.

• Molecules and Cells
• /
• v.37 no.6
• /
• pp.480-486
• /
• 2014

Growth restriction by antibiotics is a common feature that pathogenic bacteria must overcome for survival. The struggle of bacteria to escape from growth restriction eventually results in development of antibiotic-resistance through the expression of a set of genes. Here we found that some physiologically important transcriptional regulators of Pseudomonas aeruginosa including QscR, a quorum sensing (QS) receptor, SoxR, a superoxide sensor-regulator, and AntR, a regulator of anthranilate-related secondary metabolism, are activated by various growth-restricted conditions. We generated the growth-restricted conditions by various methods, such as overexpression of PA2537 and treatment with antibiotics or disinfectants. The overexpression of PA2537, encoding an acyltransferase homologue, tightly restricted the growth of P. aeruginosa and significantly activated QscR during the growth restriction. Similarly, treatments with gentamycin, tetracycline, and ethanol also activated QscR near their minimal inhibitory concentrations (MICs). Some non-QS regulators, such as AntR and SoxR, were also activated near the MICs in the same conditions. However, LasR and PqsR, other QS receptors of P. aeruginosa, were not activated, suggesting that only a specific set of transcriptional regulators is activated by growth restriction. Since paraquat, a superoxide generator, significantly activated QscR and AntR, we suggest that the oxidative stress generated by growth restriction may be partly involved in this phenomenon.

• Microbiology and Biotechnology Letters
• /
• v.39 no.1
• /
• pp.29-36
• /
• 2011

Pseudomonas aeruginosa is an opportunistic pathogen that causes various infections on urinary track, cornea, respiratory track, and burn wound site, and mainly relies on quorum sensing (QS) for its virulence. To control the infectivity of P. aeruginosa, we previously synthesized the structural analogues of a major QS signal, N-3-oxododecanoyl homoserine lactone (3OC12-HSL) to use as a QS inhibitor. Two of them (5b and 5f) had been confirmed to have an inhibitory effect on LasR, a major QS signal receptor of P. aeruginosa in the screening by the recombinant Escherichia coli reporter. To further evaluate these compounds, we tested their efficacy to control the QS and virulence of P. aeruginosa. Unlike the result from E. coli reporter, both 5b and 5f failed to affect the LasR activity in P. aeruginosa, but instead they selectively affected the activity of QscR, another 3OC12-HSL receptor of P. aeruginosa. Interestingly, their effect on QscR was complex and opposite to what we obtained with E. coli system. Both 5b and 5f enhanced the QscR activity at the low concentration range (< 10 ${\mu}m$), but high concentration of 5f (${\approx}$1 mM) strongly inhibited QscR. While 5b and 5f didn't affect the production of proteases, the key virulence factor, they significantly reduced the biofilm formation that is important in mediating chronic infections. Especially, 5f inhibited the initial attachment of P. aeruginosa, rather than the biofilm maturation. Based on our results, we suggest that 5f can be applied for an anti-biofilm agent without increasing virulence of P. aeruginosa.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2022.05a
• /
• pp.176-178
• /
• 2022

대규모 양자컴퓨터의 개발은 현재 사용하는 많은 암호화 알고리즘에 위협이 될 것으로 예상한다. 현재 NIST 는 양자 후 시대에 대비하기 위해 양자 내성 암호를 표준화 하기 위한 작업을 진행하고 있으며 이에 따라 post-quantum 시스템의 마이그레이션 과정이 필요하며 각 시스템에 QSC 적용을 위한 연구들이 이어지고 있다. 본 논문에서는 양자 후 시대에 대비하기 위해 NIST 의 PQC post quantum conference 에서 발표한 PQC 후보와 QSC 마이그레이션 과정 및 적용 방안에 대해 조사한다.

• Proceedings of the Microbiological Society of Korea Conference
• /
• 2009.05a
• /
• pp.101-101
• /
• 2009

• Journal of the Korean Society for Precision Engineering
• /
• v.19 no.9
• /
• pp.19-26
• /
• 2002

• Journal of Korean Society for Quality Management
• /
• v.47 no.1
• /
• pp.17-32
• /
• 2019

Purpose: CMMI is a process model used to assess or improve an organization's software development capabilities. This paper deals with the quality indicators when using CMMI and their priorities for possible improvement. Methods: The 22 process areas and 167 practices of CMMI are matched with 60 indicators of Quality Scorecard(QSC) first to analyze the balance of CMMI in terms of prevention, appraisal, and final result categories and second to isolate a set of key areas for quality focused performance measures. Results: A total of 86.2% (144 out of 167) CMMI practices were mapped to QSC. According to the CMMI level of maturity, level 2 and 3 accounted for more than 75% of the total. The practices at the maturity level of 4 and 5 were mapped to more than 52% of the final result's measurements. It has been observed that CMMI practices need further elaboration at higher levels to consider prevention, appraisal, and final results simultaneously. Conclusion: In order to improve the quality performance of the organization by applying CMMI, the final result measures should be refined in metrics, cycles, and methods, and then corrective actions could be conducted to improve the performance of CMMI practices. This strategy would help the practitioners benefit from CMMI in fostering the overall quality level of key activities for the organization's business goals.